In which plant, vegetative propagation by leaf takes place?
A.Sweet potato
B.Potato
C.Phalasa
D.Bryophyllum

Hint:Vegetative propagation or reproduction of vegetation is a type of asexual reproduction in which, like roots, stems, leaves, and buds, new plants are formed from the vegetative sections of the plant. It could be normal or caused artificially.

Complete answer:The process of asexual reproduction in which the multicellular structures are removed from the parents and grow into a new plant is vegetative reproduction.
The asexual mode of reproduction occurs in Byrophyllum, specifically through vegetative leaf propagation. There are notches on the margins where the meristem is present in the leaves of Bryophyllum. These are the places where epiphyllous buds originate that have the potential to develop new plants with shoots, tiny leaves, and adventitious roots. If a leaf of this plant is detached and falls on moist soil, a new plant may emerge from each bud.
Bryophyllum plant, when the leaves fall off the buds develop on the margin of the leaf, and the condition is sufficient for the growth of buds on the fallen leaf; they grow to give rise to a new plant.
In plants including sweet potato, vegetative proliferation by roots occurs. Here, buds present on the roots develop at their bases into leafy shoots above ground and adventitious roots. Vegetative stem propagation is popular in plants such as mint, onions, garlic, bananas, etc. New plants emerge here from the nodes in which buds are present.
So, option D- Bryophyllum is the correct answer.

Note: Vegetative propagation is a simple, cheap, and easier method of propagating plants compared to the conventional method of seed propagation. For instance, through this technique, some plants that normally take a few years to flower can be made to do so within a year. As the new plants are basically parent clones, they assist in preserving the next generation of useful parent characters.